Miami Beach police used excessive force in shooting teenage street artist Israel Hernandez-Llach with a Taser stun gun, and failed to give him proper medical attention afterward, according to a lawsuit filed Tuesday by his family.

The death of the 18-year-old after the Taser jolt has drawn widespread headlines, sparked rallies decrying Miami Beach police and reignited debate over law enforcement’s use of stun guns.

“We believe this investigation will illustrate that the City of Miami Beach and Miami Beach Police do not properly train or supervise their police officers in the use of force, including the use of a Taser weapon,” said attorney Todd McPharlin during an afternoon press conference on the steps of Miami-Dade’s downtown civil courthouse.

Hernandez-Llach’s relatives, who held hands and shed tears as the attorneys detailed the complaint, flanked McPharlin as he spoke.

The suit, filed in Miami-Dade Circuit Court, names the city and Police Chief Ray Martinez. It alleges that police violated Hernandez-Llach’s civil rights, and asks for damages of more than $15,000.

The “slight,” unarmed teen was suspected only of committing a “minor” crime, likely a second-degree misdemeanor, according to the suit.

As Hernandez-Llach’s friends have alleged to the media, the suit says officers “high-fived” each other while the teen lay on the ground, “illustrating a reckless disregard for [his] life and safety.” The suit suggests there was a delay in calling paramedics; Hernandez-Llach was rushed Mount Sinai hospital, where he was pronounced dead.

Miami Beach police have insisted that Mercado, who saw the teen rushing toward him, acted according to department policy in dealing with someone who was resisting arrest.

Martinez has said that under department policy, officers may use a stun gun when a person “is not in the physical control of the officer, yet poses a threat.”

The chief said this was the first time someone had died in Miami Beach after being shot with a Taser stun gun.

Taser International, the company that manufactures the weapons, maintains they provide a valuable, less-than-lethal option for restraining suspects.

“It’s a controversial subject anytime a tragic death occurs,” a company spokesman told the Miami Herald recently. “I’m a parent, I feel for his parents . . . but we have to wait for the science and the facts to come out.”

The company has suggested officers try to avoid shooting suspects in the chest, as was done in Hernandez-Llach’s case, because of the risk of cardiac arrest in some people.

The Miami-Dade Medical Examiner’s Office is investigating the cause of death while awaiting toxicology tests, which could take a few more weeks.

In previous deaths involving Taser stun guns and law enforcement, medical examiners across the nation have usually pinpointed complications resulting from drug use as the cause of death.

The Florida Department of Law Enforcement also will review a Miami Beach internal investigation, while Miami-Dade prosecutors, as is routine for in-custody deaths, will determine whether any laws were broken.

McPharlin said Tuesday that the lawsuit would serve as an “avenue” for the family to investigate the death of the teen, a sculptor, painter and photographer known as “Reefa.” He was also known for his art on the city’s abandoned buildings while playing cat-and-mouse with cops, who, like many property owners, consider graffiti taggers to be vandals, not artists.

But police documents and answers will not necessarily come quickly.

In most cases, police will not release most documents related to probes of in-custody deaths or fatal shootings until prosecutors have concluded their investigations. That can often take months, or even years, depending on the complexity of the case and how quickly police turn over evidence to the state attorney’s office.